Telephone



(No Model.) Q

' J. P.,M0DERMOTT.

Telephone.

No.231,599. PgtentedAug. 24,1880.

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UNITED STATES PATENT EETcE.

JOHN P. MGDERMOTT, or eALvEsToN, TEXAS.

TELEPHONE.

SPECIFICATION forming part of Letters Patent No. 231,599, dated August 24, 1880.

Application filed Apri120, 1880. (1% model.)

To all whom it may concern:

Be it known that I, JOHN P. MGDERMOTT, of Galveston, in the county of Galveston and State of Texas, have invented a new and useful Improvement in Telephones; and I do hereby declare that the following is a full, clear, and exact description of the same, reference being had to the accompanying drawings, forming part of this specification, in which- Figure 1 is a view of the telephone with the receivers and transmitter in section, and with the transmitter thrown up over the magnet forming the support which passes over the top of the head. Fig. 2 is an inside face view of the outer half of the transmitter. Fig. 3 is a side view of the telephone applied to the head of the operator. Fig. 4 is an inside face view of the outer half of that receiver below which it is placed on the sheet of drawings. Fig. 5 is a' corresponding view of the other receiver. Fig. 6 is a diagram representing the circuits and the connect-ions of the various wires of the telephone thereto.

The object of this invention is to provide a telephone enabling one to hold conversation in any position and listen without inconvenience to lectures, 850., without others in said persons presence hearing the same, and to prevent other sounds from interfering with those to he heard, and at the same time allow absolute freedom of the hands when speaking and hearing; and it consists, first, in a set of U-shaped elastic magnets adapted to be supported by the head of the person sending and receiving messages, the ends of said magnet or magnets connecting the receivers and fastened by a screw-core or other means; second, in the peculiar construction and arrangement of the transmitter attached after the manner of a swinging bail to the receivers, so as to allow its being turned into or out of position for speaking purposes; third, providing supports for the telephone when not in use having such connection with the main line, primary, secondary, battery, and call bell wires as will, when properly placed, bring the battery, primary, and call-bell wires alone in line.

For the sake of greater clearness I will first describe the detailed construction of my telephone, and then its application to the circuits.

Referring to Figs. 1 and 3, A represents a considerable elasticity and form an expansible' support adapted to rest upon the top of the head, while an elastic cloth strip, A, passes behind the head and holds the magnet A in place. At each end of magnet is arranged a receiver composed of a non-conducting earpiece, B, and hemispherical block B, between which is fastened by screws a metal diaphragm, C.

To the hemispherical blocks B the extremities-0t the magnet A are attached, passing around in a groove on the convex side of the block and in metallic contact with the screwcore D, whose head serves to secure ends of the magnets to the block.

Around the inner end of the screw-core and within a recess in the inner face of the block is disposed a bobbin, E, wound with wire.

Just below the point where the ends of magnet A terminate and are held by the screwcores are placed a similar set of laminated plates, A which at one end are held by the head of the screw-cores and at the other rest against the diaphragms.

Between the ear-pieces and the semi-cylindrical blocks of the receivers are hinged the ends of the bail-shaped support F F for the transmitter, the said transmitter being connected therewith, so as to complete the semicircle and allow the transmitter to be swung up over the bowed magnet on the head out of the way or dropped down into a horizontal position before the mouth, the said transmitter being connected with its supports by spiral springs H H, which permit it to be stretched to suit the size of the head of the operator.

The transmitter consists of a non-conductin g mouth-piece, G, and a hemispherical block, G, which latter carries upon its inner face two semicircular plates of carbon, at a, insulated from each other and connected by wires with the two metal strips 2) b, which are in electrical contact with the springs H H, but are insulated from each other in the center, and are held at this point bya nonconducting washer and a screw, 0.

The face of the mouth-piece of the transmitter next the block G has a circular recess, in which is placed loosely a disk of carbon, J, which is free to vibrate upon the semicircular pieces of carbon behind it.

The electrical connections are made as follows: One of the semicircular carbons, a, of the transmitter is connected to one of the springs, H, and the transmitter-support F on that side, and the other carbon, to, is connected to the spring H on that side and the transmitter-support F, leaving the front or free carbon free to vibrate and connect the two semicircular plates. One of these transmitter-supports, F, is electrically connected to a pivotal screw on the right-hand receiver, which screw is connected to a wire, d, which wire is insulated and passes up under the silk folds wrapped around the bend of magnetA, thence down to the left receiver, and through a groove to the binding-screw and wire No. 3. The other support, F, is connected to its pivotal screw in the left-hand receiver, which screw connects with a wire, 0, laid in a groove, and which wire passes to a binding-screw and wire No. 4. For the receivers one end of the left helix passes by wire f to the binding-screw and wire No. 1., while the other end, g, of the wire of the same helix passes under the silk folds of the large magnet to the helix in right receiver, thence back, by wire g, beneath the silk folds again to left receiver, and thence to binding-screw and wire No. 2.

The several wires 1 2 8 4 of the telephone are connected in circuit, as shown in Fig. 6, in which Ais an induction-coil, with a callbell and armature for ringing the same, and E H and F D two pairs of spring-jaws, between which the receivers of the telephone are hung up when out of use, and by which the circuits are controlled. These said jaws are made of metal, hinged at their centers. A

spring (not shown) tends to throw their outer 7 ends against contact-screws on their sides connected with the circuit-wires. The telephone, when hung up as shown in dotted lines, is pressed in between the lower ends of the jaws, opening them at the bottom and closing them at the outer or upper end, breaking at the same time contact with the two contact-screws at the top and making connection below. Now, although the telephones in Fig.6 are shown in full lines removed from their 'supporting-jaws, yet the said jaws are, for greater clearness, shown in the position which they occupy with relation to their contact-screws when the telephone is hung up between the jaws, as indicated in dotted lines. Now, if it is required to make the induction-coil work the call-bell through the primary alone, then wire Sis dispensed with. Now let operator B press the button at his end, making connection between battery and jaw H, and a current will then flow from ground through E H, battery, primary coil, attracting the armature, through 5, jaws F D, wire 6, to line.

vIf required to work the call by secondary alone, then the secondary is permanently connected to jaw D, and wires 5 and 6 dispensed with. Then the current flows from ground, through E H, battery, wire 8, jaws F D, secondary, (attracting armature,) and to line. If it is required to have both primary and secondary work the call-bell, then wires 6 and 8 are dispensed with. The current then flows from ground, through E H, battery, primary, wire 5, jaws F D, and secondary, to line.

When the telephone is taken down and spoken into, the current from the transmitter flows in local circuit through wire 3, jaws E H, battery, and primary back to transmitter by wire 4. The induced current passes from ground through wire 2 and receivers out by way of wire 1, jaws F D, and secondary to line. It is of course understood that the undulating currents produced by the voice are not sufficient to attract the armature.

It will be noticed that both batteries are made use of in all connections which might have a tendency to enhance the value of using the induction-coil, as a substitute for the electro-magnet, which electro-magnet is superfluous, as the call-bell is never used when the induction-coil is, nor is the induction-coil used when the call-bell is.

In the larger transmitter a thin circular plate of zinc may be substituted for the free carbon diaphragm, in which case no battery is required, the necessary chemical action being brought about by the moisture of the breath, and the plate vibrating with the voice sets up an undulating currentin correspondence therewith, which, as a necessary consequence, will act accordinglyon the diaphragm of the receiver.

Having thus described my invention, what I claim as new is- 1. The combined magnet and support A, composed of thin elastic plates of steel grouped together, as described, and having at their terminals ear-pieces and helices, forming receivers, as shown and described.

2. The receivers composed of diaphragm O, non-conducting ear-piece B, and hemispherical block B, having a bobbin, E, in its inner face, and a screw-core, D, in combination with the magnet A and magnetic section A, arranged in a groove on the convex side of the receiver and clamped by the screw-core, as described.

3. The combination, with a pair of receivers connected by a bowed support for the head, of a transmitter mounted in a bail-shaped swinging frame and jointed to the receivers, so as to be turned up over the head or down in front of the mouth, as described.

4. The transmitter consisting of the two separable pieces G G, the conducting-strips b b, insulated from each other, and held by a non-conducting washer and a set-screw, c, the semicircular insulated carbon plates (Ml/,COH- nected,respectively, with the strips 1) b, and the loose disk J, adapted to connect a and a,

all combined substantially as and for the purary circuit with contactpoints, arranged in repose described. lation to the j aws substantially as shown and 10 5. The combination of the following eledescribed. ments: the U-shaped telephone having receivers altits extremities and conducting-wires 1 JOHN MGDERMOTT' 2 3 4, the two pairs of jaws E H and F D, Witnesses: adapted to receive the two receivcrsof the tele- M. MGDERMOTT, phone, a call-bell, and a primary and second- E. J. FIVEL. 

